The Milky Way Reveals the Stellar Community We Live In
+ Von Del Chamberlain +
...torrent of light and river of the air,Longfellow, The Galaxy
Along whose bed the glimmering stars are seen
Like gold and silver sands in some ravineM-^E
A few years ago I was on a cruise ship heading northward along the coast of South America. It was my job to help people aboard enjoy the night sky as we moved along. On one fine evening I was heading out do my work when I encountered the hostess, a well educated, very attractive and articulate British woman. I told her what I was about to do. "We will look at the Southern Cross and many other constellations; we will learn to recognize specific stars and lots of interesting things about them; we will see the Milky Way in all its glory, and . . . "
"Is it out there?" She asked. "What does it look like. I have never seen it."
"It is a soft luminous river that whispers the story of the great Galaxy we live in," I said. "It is much better than I can describe to you. You must see it for yourself. Come, it will only take a few moments."
"Is it actually there right now?" she wanted to know. The eagerness in her voice suggested I had a new student.
"Yes!" I said, "Lets go take a look."
Then her voice changed. Perhaps she thought about the long walk to the end of the ship. Maybe she just thought of the time it would take. "I'll try to come sometime," she replied, to end the conversation. She never did. Not that night, nor any other. I wonder if she has seen it yet? I wonder if she ever will? I still wonder, as I have for years, what it is that makes us care so littleabout things so big and significant. Nothing we can see with our eyes is more impressive or more important if we wish to understand the cosmos and our place in it. How many people are there who will never see the Milky Way in their entire lives?
Today we know more about the universe than ever before, yet fewer people have direct experience with it. What a sad loss to not know the inspiration of starlight.
From mid-July throughout the rest of the summer the Milky Way is nicely placed for observation. On a clear moonless night, when it has become very dark out in the country away from city-glow, you can savor one of the most inspiring vistas the human mind has ever beheld. As Llewelyn Powys wrote:
No sight that human eyes can look upon is more provocative of awe than is the night sky scattered thick with stars.
The Milky Way has been thought of as a river of light, as a pathway of spirits traveling to the hereafter, a trail of corn meal scattered by Coyote, or the "Winter Street," as well as milk sprayed across the heavens. Time, thought, experimentation and huge amounts of observation using the greatest scientific technology in world history has revealed to us that it is actually the combined light of vast numbers of stars that define the plane of the Milky Way Galaxy we live inside of. A few hundred billion stars arranged in a flattened spiral spanning 100,000 light years composes our stellar city. It is difficult to know the whole starry town from our position inside. Sun, Earth and all of us are located about two-thirds of the way out in the suburbs.
Quite early on it was suspected that we lived in such a place, but it was not until large telescopes gave us the power to clearly view other galaxies that we correctly guessed what the Milky Way might look like if we could see it from afar. From where we are, we look around to see stars in all directions, but the Milky Way dominates our view, covering one-fifth of the entire sky. Along its path we find vast numbers of stars, dimmer and dimmer farther out, light blending into the creamy trail. With the invention of radio telescopes, we were able to observe essentially the whole galaxy and compare it with others we see millions, even billions, of light years away.
What an amazing object is the Milky Way Galaxy! Hundreds of billions of stars gatheredinto a giant pin-wheel, each star carrying whatever planets it might posses, the whole galaxy gliding amid a field of galaxies. What delight to discern a portion of this on a dark summer night!
Think as though you can travel out into our stellar city, to visit the finest art gallery in the universe where you behold the most inspiring exhibition ever imagined. A short drive out of city lights, on a clear dark night, perhaps to a high place, or onto a broad valley without mountains, cliffs or trees to obstruct your view, will take you into the corridor of astronomical delights. Two or three hours after sunset your eyes and mind adapt, and you swim in the flow of light from myriads of stars. The sight is undescribable: you yearn to reach up and touch them; instead, they reach down to you with photons carrying all the information we can ever glean about them.
The dark lane of the "Great Rift" takes you down the Milky Way toward the South, where just above the horizon, in the constellation Sagittarius, your eyes find star clouds, and your binoculars give you bright nebulae and clusters of stars, the tapestry of time from star birth amid clouds of dust and gas to old age in compact swarms. Browsing low in the south, where the Milky Way is brightest, you peer toward the center of the galactic city. Below the southern horizon, where we cannot see from our latitude, the Milky Way continues: indeed, it forms a complete circle around us.
Even though it has taken all of human history to obtain the understanding we possess, great thinkers of the past used just their eyes and minds to make astonishing guesses about the cosmos. In 1755, philosopher-scientist Immanuel Kant reasoned that we must live inside a metropolis of stars outlined by the Milky Way. The path of starlight was a beacon for his life. He wrote:
Two things fill my mind with ever new and ever greater wonder and reverence, the oftener and the longer I allow my mind to dwell upon them: the starry heavens above and the moral law within me.
The evidence has been there throughout human history, streaming down as beams of light available to watching eyes or instruments. That same inspiration was there, for Kant, Newton, Einstein, and it is there for you to personally experience the outpouring of beauty from the wondrous majestic galactic community we belong to.